Now that I'm using warnings (just to see what it can do for me in this particular case) I discovered some new problems which I shouldn't have discovered without warnings turned on.
For example, I allowed a value to be used even if it were not initialized. But now I discovered situations in which this variable was undef or empty while it should have had a value.
This runtime checking mechanism look very very useful, I'm very surprised!

Thnx a lot
Luca